With the development of space technology, a growing number of the earth observing satellites have been used to acquire data of the earth for various purposes, and the capability of data acquirement from spaceborne sensor makes a rapid enhancement. Under this circumstance, it is very important to measure the capability of data acquirement quantitatively. This paper concerns on the measurement of EOS data acquirement. This measurement can identify access area of a specific EOS. Considering the characteristics of payload, the location of instantaneous imaging area could be calculated based on sensor geometric model. To calculate the location of a given sensor instantaneous imaging area, the measurement is divided into 3 stages: firstly, a satellite motion prediction is undertaken for the purpose of getting position and velocity of the satellite; furthermore, considering the performance of skew maneuver, the imaging area of the satellite's sensor could be calculated based on strict geometric model, finally, the imaging area of sensor is calculated. Experimental results show that the proposed measurement is accurate.